Autosomal recessive inheritance

MedGen UID: 141025, Concept ID: C0441748, Intellectual Product

Source: HPO, OMIM, Orphanet

A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in homozygotes. In the context of medical genetics, autosomal recessive disorders manifest in homozygotes (with two copies of the mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). [HPO:curators]

(HPO, OMIM, Orphanet)

Summary

Spinal muscular atrophy (SMA) is characterized by muscle weakness and atrophy resulting from progressive degeneration and loss of the anterior horn cells in the spinal cord (i.e., lower motor neurons) and the brain stem nuclei. The onset of weakness ranges from before birth to adolescence or young adulthood. The weakness is symmetric, proximal > distal, and progressive. Before the genetic basis of SMA was understood, it was classified into clinical subtypes; however, it is now apparent that the phenotype of SMN1-associated SMA spans a continuum without clear delineation of subtypes. Poor weight gain with growth failure, restrictive lung disease, scoliosis, joint contractures, and sleep difficulties are common complications.

Clinical features

HelpList of clinical features of the condition/phenotype displayed from sources such as the Human Phenotype Ontology (HPO) and OMIM. For more information about the disease, please go to the disease information page.

Consumer resources

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